1. Field of the Invention
This invention relates to a drum lock device for chemical- and hazardous-waste containers, and, more particularly, to a lockable bolt structure for an open-head drum wherein, upon a padlock being emplaced through the bolt, the driver portion of the bolt is covered by a free-spinning shroud.
2. Information Disclosure Statement
In preparing for this application, a pre-examination patentability search was performed. In the search, the following fields and respective periods covered were examined.
______________________________________ CLASS/SUBCLASS PERIOD COVERED ______________________________________ 70/164 07/23/1878 to 09/26/1989 70/165 02/26/1878 to 08/15/1989 70/230 05/31/1904 to 07/04/1989 70/231 09/18/1923 to 10/24/1989 ______________________________________
Upon search, the following patents were uncovered:
______________________________________ ISSUE ITEM NO. U.S. PAT. NO. INVENTOR DATE ______________________________________ 1 1,467,254 A. Tarbet 09/04/1921 2 1,832,057 E. G. Stein 11/17/1931 3 2,526,238 L. B. Kendall 10/17/1950 4 4,300,373 W. M. Camos et al 11/17/1981 5 2,143,925 M. J. Schlitters et al 01/17/1939 6 4,302,137 H. Hart 11/24/1981 7 4,427,326 S. C. Hobson, et al 01/24/1984 ______________________________________
In considering the various patents uncovered, Items 1 through 4 relate to a means of securing a closure ring. The patent to Camos et al, U.S. Pat. No. 4,300,373 (Camos '373), discloses the enclosing of the bolted connection between two flanged fittings commonly found in the oil and gas industry and known familiarly as a "Christmas tree".
The patents to Tarbet, U.S. Pat. No. 1,467,254 (Tarbet '254), and Kendall, U.S. Pat. No. 2,526,238 (Kendall '238) show retaining bands that annularly surround the closure cap and the flange upon which the cap rests.
Next, turning to Items 5, 6, and 7 various bolt structures are shown with shroud-like covers for the nut elements.